Excel Wizard Needed

[fjmeat]

I need a simple excel page with formula showing the following "Future Investment"

Part 1
Initial Investment: $5000
Monthly Contribution: $100/mo
Monthly Contribution stops after: 7 years
The above is compounded at 7% interest

What is total contribution including compounded interest?

Part 2
No more monthly contributions are made.
The investment goes for 40 more years at 7% compounded interest.

After all 47 years, how much money is in the account?

Here's a calculator to prove the work, but I can't seem to get my Excel sheet to function to match: http://www.daveramsey.com/article/investing-calculator/lifeandmoney_investing/#/entry_form 😕

 

[postmark]

=FV(<interest rate>/12,<years to grow with no contributions>*12,,FV(<interest rate>/12,<years to contribute monthly>*12,<monthly contribution>,<initial investment>,1),1)

 

[postmark]

Hopefully that worked for you. Love people that ask questions, then never return to post follow ups.

 

[fjmeat]

Hopefully that worked for you. Love people that ask questions, then never return to post follow ups.

Thanks for the bump. Actually it did work! But compared to two others that I've tried, yours is giving me a different answer. I still trying to figure out what the difference is...

 

[mpo]

Some financial programs use 360 days for the year when calculating the daily compounding rate.

e.g., P(1+r/12)n * (1+(r/360*d)) -P

 

[hardhat]

Postmark's formula was for monthly compounding interest, not daily. Also, the last part specifies whether the first monthly payment is made beginning of the first month or after the first month (0 or 1).

 

[postmark]

Yes, I did monthly compounding since the site linked also claimed to assume monthly compounding.

Also, when you say it's a different answer, how much is it off? I see if I use your numbers on that site and in excel that site gives you $310,128.05 while the excel sheet gives you $310,126.71 which is off by $1.34. My guess is it's a rounding issue somewhere.